1. Field of the Invention
This invention relates to apparatus for winding up a web section without using a core, and in which the web section has been torn along a transverse perforation line from a web which is continuously supplied and provided with spaced transverse perforation lines.
2. Description of the Prior Art
In winding apparatus of the type disclosed in West German Patent Publication No. 21 27 128, winding pins, which in the winding position protrude freely over the width of the web, are secured to the free ends of levers, which are pivoted in a winding head and are held, e.g., by springs, in their inner, retracted position. The winding pins can be pivotally moved to their spread position by an axially displaceable mandrel, which has a conical end portion that engages corresponding cam faces of the level. That apparatus has a relatively expensive structure because the protruding winding pins must be extended and retracted substantially throughout the width of the web which is to be wound up, and as they are extended the pins must be be spread relative to each other to such an extent that the web can move freely between the winding pins to the other winding station.
West German Utility Model Specification No. 77 12 942 discloses winding heads which are provided with winding pins, which in their non-spread position are sufficiently spaced apart to permit the web to move between the winding pins. but the winding pins must protrude freely over a large length beyond the web to be wound so that they can be bent outwardly to their spread position by a spreading cone.
Swiss Patent Specification 487,791 discloses a winding apparatus having a winding station which is fixed to the frame and includes two mutually opposite pairs of winding pins, which are connected to rotary drive means and are adapted to be advanced toward a web that is to be divided into sections that are to be wound up without using a core. The two winding pins hold the web therebetween and are retractable from the side edges of the web when a roll is to be released. That apparatus serves for intermittent winding of web sections which have been severed from a continuous web. The winding pins are displaceable in a common plane toward and away from each other, and as they are advanced they move like tongs to grip the web. As they are retracted they perform a corresponding closing movement to reduce the frictional coupling between the winding pins and the roll, which can then easily be stripped from the winding pins. The roll, which is still connected to the web, then falls into a receiving tub. The means for severing the web from the roll includes pairs of gripping jaws disposed on opposite sides of the winding station, and a cutting knife is disposed between the pairs of jaws. Before the web which is gripped by the jaws is severed, the web is tensioned by a tensioning device so that the properly aligned and spread winding pins can be advanced toward each other in order to engage the web. That winding apparatus does not permit a winding up and severing of a continuously supplied web. The web must be stopped for the severing of each roll consisting of a web section having a predetermined length, and it must be gripped by separate gripping means on both sides of the winding station and must be severed by a separate cutting device. As a result, the winding rate is restricted and the structural expenditure is increased.
It is an object of the present invention to provide web winding apparatus and in which the winding of the web sections to form supply rolls requires smaller axial displacements and smaller radial spreading movements of the winding pins.